assert true
assert !false

assert ('a' =~ /./)
assert !('a' =~ /b/)

// Las colleciones no deben ser vacias
assert [1]
assert ![]

// Los mapas no deben estar vacios
assert ['a':1]
assert ![:]    

assert 'a'
assert !''

assert 1
assert 1.1
assert 1.2f
assert 1.3g // Big integer
assert 2L
assert 3G
assert !0

assert new Object()
assert !null